Looks like it could be a problem with the window or do you have ground sloping towards the house or is the dirt against the house above the tar and stuff. I wouldn't close up the walls before you have solved this.

Those poured walls have an imitation concrete block face on the interior.

Judging from the leaks and other cracks, you have significant shrinkage in the walls that is typical with a quick pour and dump poured wall construction.

Obviously, the surface grading that sheds the water from rains and downspout extensions is the first thing to look at. After that, look at installing drain tile (either exterior or interior). If you have to excavate to apply a proper waterproofing an exterior system is viable. If you have landscaping and patios, sidewalks, attached garages an interior system may be better.

1) I have a exterior drain tile system already installed...and since water is flowing into the sump box, I can only assume it is working well. There is no other water on the walls.

2) As for the rain spouts...all my spouts drain into a drain system and flow into the street "watershed" system...so my downspouts are all connected and there is no "excess" water from the spouts.

3) I do have landscaping, and to the best of my ability it does appear to slope away from the house. HOWEVER the mulch is against the concrete and the "waterproofing" system does not go that high up...

4) I do have a few cracks in the concrete...i was told by two "experts" when the house was built that this is relatively normal with poured concrete walls...perhaps I got scammed...but nothing I can do about that at the moment. This is the only crack that is leaking at the moment.

So with these new facts...could the mulch alone cause this? Don't I need to also figure out how to seal the crack as well as try to fix the mulch issue?

What if topsoil is up against the concrete as well (sloping away)...and the tar/foam is below that grade. Do I need to remove all the topsoil against the sides of the walls?

Finally, I had a neighbor tell me they had this problem and had someone inject a polyethelene (sp) foam of some sort that massively expands and seals the crack all the way through?

Concrete will soak up water from wet soil so for starters I would lower the level below that of the seal outside. In fact I would dig down the outside around the area of the leak and see what is happening with the water there. I expect that the leak is at the top of the wet stain and you could repair the leak from outside. When they pore the concrete they have a steel tie that holds the forms together and sometimes these ties rust out and creates a leak. I would also take a real close look at the window sill and how it is sealed.